This invention relates to an apparatus for removing tissue or organs from a patient's body. More particularly, this invention relates to laparoscopic instrument having an encapsulating sheath to aid in capture and withdrawal of tissue or organs.
Laparoscopic surgery often requires dissection or severance of diseased or otherwise infected organs or tissue present in a patient's abdominal cavity. However, retrieval of the dissected or severed tissue or organs can present problems of contamination of overlying abdominal muscle tissue when the tissue is removed from the patient's body. When the laparoscopic instrument is withdrawn from a patient's body, bits of diseased tissue can contact and possibly infect the remaining healthy tissue as the laparoscopic instrument is withdrawn from the surgical site. While many laparoscopic devices are known for grasping and retracting severed organs or tissues, none provides a simple mechanism for sterile screening or shielding of healthy tissue from severed, diseased tissue during retraction of the laparoscopic instrument from the patient's abdomen.
In the field of urology, devices are known for encapsulating and extracting kidney stones from human body passages. Generally, only small pieces of stone are retracted using these devices because of the small size (device size is limited by the small radius of the relevant body passageways) of the urological devices. A typical urological device has a catheter that is generally no greater than 4 mm to allow its ready entrance and movement along the body passageways.
For example, U.S. Pat. No. 4,927,426, issued to Dretler on May 22, 1990, describes a catheter device for capturing and holding kidney stones. This catheter is formed from an elongated tube having a cuff portion disposed on one end. The cuff portion can be actuatably collapsed inward into the tube and a snare is disposed and actuatably movable within the catheter for capturing and holding a kidney stone and collapsing the cuff portion to surround the kidney stone. However, rather than risking injury to narrow body passages by withdrawing an ensnared kidney stone, the kidney stone is typically disintegrated in place in the body passage using known lithotriptic methods.
U.S. Pat. No. 4,611,594 issued Sep. 16, 1986 to Grayhack et al. also discloses an instrument useful for containment of calculi found in body passages or organs. In one embodiment of the disclosed apparatus, the distal end portion of a catheter is provided with several expandable gussets that permit enlargement of the catheter's distal end as the working end of the grasping device, and any stone grasped therein, are retracted into the catheter. In other embodiments disclosed, struts of an open-ended basket are bridged by a flexible membrane or web that can close over calculi.
U.S. Pat. No. 4,997,435, issued Mar. 5, 1991 to Demeter, discloses a percutaneous catheter with an encapsulating receptacle. Several struts extend from their attachment to a first catheter, giving a cup-shaped form. A sheath is attached to cover the struts.
U.S. Pat. No. 4,243,040, issued Jan. 6, 1981 to Beecher, discloses a device for removing objects from human body passages. The disclosed device is useful for removing kidney stones, gall stones, and other objects from human body passages. A thin, rubber, tubular sleeve inflatable by fluid pressure, forms a soft annular convex portion that bulges beyond a distal end of a inner tube for receiving engagement with a stone. The stone is captured by suction applied by the inner tube. The inner tube is retracted into the sleeve while progressively turning the sleeve inside out around the stone to envelop it for removal from the tubes.
In contrast to these small diameter urological devices, the present invention is a tissue or organ retrieval apparatus particularly useful for retrieving large bits of tissue or even small organs (for example gall bladders and ovaries) during laparoscopic procedures. The apparatus includes a longitudinally extending tube having a tip end insertible into a patient. The tip end of the tube is quite large compared to urological devices, often having a diameter of between about 5 mm to about 15 mm or more, although it is more typically from about 5 mm to about 9 mm in diameter. The tip end of the longitudinally extending tube is formed to be radially expandable in response to withdrawal of tissue into the tip end of the tube.
Tissue can be withdrawn into the tip end of the tube by using graspers, pincers, nets, baskets, suction applying devices or any other device that can be extended to engage and hold tissues or organs with sufficient force. To reduce the possibility of contamination of healthy tissue, an elastic sheath is attached (typically by welding or with an elastic adhesive) to cover the tip end of the tube. The elastic sheath is formed to radially expand in response to radial expansion of the tip end of the tube during withdrawal of tissue into the tip end of the tube.
In preferred embodiments of the invention, four peripherally spaced, longitudinally directed slits are symmetrically arranged about the tip end of the tube to promote substantially even radial expansion of the tip end of the tube. A reciprocally movable grasper may be positioned to extend through the longitudinally extending tube. The grasper may be formed to define a pair of movable, opposing jaws that can be mechanically urged together for grabbing and holding severed or dissected tissue as the tissue is drawn into the tip end of the tube. As indicated above, a number of different types of devices may be used to grasp or hold a piece of tissue or an organ to pull it up into the tip end of the tube.
Another embodiment of the present invention provides a laparoscopy device for use in surgical operations in which an organ is severed from the body. The device includes a tubular element for penetrating into the body. The tubular element has a proximal end portion outside the body and a distal end portion inside the body adjacent the organ to be removed, and further defines a central axial passageway through which various surgical instruments are inserted from outside the body to the organ to be removed. The distal end portion of the tube is formed to resiliently expand radially outwardly. For instance, the tube may be formed to have a grasper for grasping the severed organ and pulling it into the distal end portion of the tubular element to be held by said finger portions is provided, and a flexible, elastic sheath covering the distal end portion is also provided. The sheath has an open end mating with the open end of the distal end portion so that when the severed organ is grasped and pulled into the distal end portion the sheath encloses the distal end portion, grasper and severed organ for removal from the body.
Still another embodiment of the present invention provides a tissue retrieval apparatus for removal of tissue from a patient's body. The apparatus includes a cannula formed to define a channel therethrough, the cannula having an outer wall and an inner wall, and a plurality of ribs longitudinally extending to connect the outer wall and the inner wall. Channels are also defined between adjoining ribs. The cannula has a tip end insertible into a patient, with the tip end of the cannula being formed to define a plurality of longitudinally directed slits to allow expansion of the tip end of the cannula in response to withdrawal of tissue into the tip end of the cannula. A mechanism is provided for withdrawing tissue into the tip end of the cannula. Preferably, graspers, tweezers, suction, or other conventional mechanisms are used. In addition, an elastic sheath is attached to cover the tip end of the cannula. The elastic sheath is formed to expand in response to expansion of the tip end of the cannula upon withdrawal of tissue into the tip end.
In preferred embodiments, the withdrawing mechanism includes a conduit piece formed to define at least one passageway. This conduit piece is connected in fluid communication with the channels of the cannula to allow passage therethrough of grasping instruments, and/or suction intake of tissues or fluids. The conduit piece may be sealed, and may also have a valve mechanism for controlling fluid flow in the at least one passageway of the conduit piece. In certain embodiments, the conduit piece is formed to define first, second, and third passageways, the first passageway being connected to the channels of the cannula, the second passageway being connected to the sealing mechanism, and the third passageway being connected to the valve mechanism.
The sealing mechanism may include a compressible annular seal positioned to seal the second passageway, a mechanism for compressing the compressible annular seal to provide an airtight seal across the second passageway, and a duckbill flap valve positioned in the second passageway. The duckbill flap valve may have first and a second flaps biased to sealingly engage each other, the first and second flaps being configured to move apart to permit passage therethrough of a medical device (such as graspers, secondary cannulas, etc.) inserted through the conduit piece.
The foregoing described embodiments and other aspects of the invention will be better understood with reference to the following description of the drawings.